A Randomised Controlled Trial of Oxygen Therapy in Acute Myocardial Infarction (AVOID - Air Verses Oxygen In myocarDial Infarction Study)
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 638
- 试验地点
- 20
- 主要终点
- Myocardial Infarct Size
研究概览
简要总结
- Aim
The AVOID (Air Verses Oxygen In myocardial infarction) trial is designed to determine if the withholding of routine oxygen therapy in patients with acute heart attack leads to reduced heart damage compared to the current practice of routine inhaled oxygen for all patients.
- Background
There is evidence supporting and refuting the current practice of providing oxygen to all patients with acute heart attack. A recent summary of clinical trials suggested that oxygen may increase the degree of heart damage during heart attack. It also highlighted that the few trials into oxygen therapy were performed before the use of modern medications and procedures to treat heart attack and that further studies were urgently needed, using contemporary practices.
- Design
A total of 334 patients will participate in this randomized controlled trial. Patients in this study will receive the best current management and care for their condition. Patients will be randomized to routine pre-hospital care with oxygen therapy vs pre-hospital care without oxygen therapy. Patients will then receive standard hospital care, aside from allocated oxygen or no oxygen therapy. The primary outcome measure of heart damage will be investigated using routine blood tests. With additional information gathered from other aspects of routine heart care including coronary angiogram, electrocardiograms and complications of hospital stay. Patients will be followed up at 6 months to determine any longer term effects of treatment.
详细描述
Coronary artery disease (CAD) is a leading cause of morbidity and mortality in Australia[1]. In particular, many patients with CAD present with ST-elevation myocardial infarction (STEMI) as a result of acute thrombotic coronary artery occlusion. The optimal treatment for patients presenting with STEMI is reperfusion therapy either with primary percutaneous coronary intervention (PCI) or administration of a thrombolytic drug[2, 3].
Current guidelines recommend additional treatments for patients with STEMI prior to reperfusion therapy, such as oxygen, aspirin and nitrates[4]. Whilst there is supportive evidence from clinical trials for the administration of aspirin[5] and nitrates[6], there is no data from prospective, randomised, controlled clinical trials to support the use of routine supplemental oxygen.
For many years, the administration of supplemental oxygen has been considered beneficial for the treatment of patients with acute myocardial infarction largely based on experimental laboratory data. For example, in a laboratory study, anaesthetised dogs underwent coronary artery occlusion and were then administered either 21% oxygen, 40% oxygen or 100% oxygen. In the 40% oxygen group, there was decreased myocardial injury and infarct size compared with the air or 100% oxygen groups[7].
In another laboratory study, two groups of dogs underwent 90 minutes of coronary occlusion followed by 72 hours of reperfusion[8]. One group received 100% inspired oxygen from 20 minutes before reperfusion and three hours after reperfusion whereas the air group received room air. The infarct size in the oxygen group was reduced by 38% and left ventricular ejection fraction was improved compared with the dogs receiving room air. This data suggests that high concentrations of inspired oxygen may be of benefit in acute myocardial infarction followed by reperfusion therapy.
However, there is increasing clinical data that suggests that oxygen administration before and during reperfusion in patients with STEMI may be harmful.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults ≥ 18 years of age.
- •Chest pain for < 12 hours
- •ST-elevation Myocardial Infarction including either: 1) Persistent ST-segment elevation of ≥1mm in two contiguous limb leads; 2) ST-segment elevation of ≥ 2mm in two contiguous chest leads, or; 3) New left bundle branch block (LBBB) pattern.
- •Able to be transported to a participating hospital
排除标准
- •Hypoxia with oxygen saturation measured on pulse oximeter < 94% with the patient breathing air
- •Bronchospasm requiring nebulised salbutamol therapy using oxygen
- •Altered conscious state
结局指标
主要结局
Myocardial Infarct Size
时间窗: At 72 hours post infarct
The primary end-point for the study will be infarct size at hospital discharge which will be ascertained by the routinely collected cardiac biomarkers during hospital admission such as cardiac troponin I (cTnI) and creatine kinase (CK)Infarct size will be evaluated via blood test on admission and then 6 hourly tests for 48 hours and 12 hourly measurements between 48 hours and 72 hours. Infarct size will be measured by: * Mean and peak cTnI * Mean and peak CK * The area under the curve of CK and cTnI release over the first 72 hours of reperfusion.
次要结局
- Myocardial Salvage(4 days and 6 months)
- ST segment resolution(1 day post reperfusion)
- TIMI Flow(At completion of coronary intervention procedure)
- Survival to Hospital Discharge(Any)
- Major Adverse Cardiac Events (MACE)(6 months)
研究者
Ms. Rowan Frew
A.Professor Stephen Bernard
Bayside Health